Haptic feedback assembly

ABSTRACT

A haptic feedback assembly includes interconnections for mechanically and electrically securing a haptic actuator in a track pad assembly so as to securely and efficiently provide haptic feedback to a user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-provisional patentapplication Ser. No. 14/792,267, filed Jul. 6, 2015, and titled “HapticFeedback Assembly” which claims priority to U.S. Provisional PatentApplication No. 62/057,751, filed Sep. 30, 2014 and titled “HapticFeedback Assembly,” and U.S. Provisional Patent Application No.62/129,943, filed Mar. 8, 2015, and titled “Haptic Feedback Assembly,”the disclosures of which are hereby incorporated herein by reference intheir entirety.

FIELD

The present invention generally relates to an electromagnetic actuatorfor providing haptic feedback in a computing device, and moreparticularly to an electromagnetic actuator that is mechanically andelectrically secured to a force-outputting plate.

BACKGROUND

Haptics is a tactile feedback technology that pertains to the sense oftouch by applying forces, vibrations or motions to a user. Thismechanical stimulation may be used to provide tactile feedback inresponse to an input command or system state. Haptic devices mayincorporate actuators that apply forces or motion for providing touchfeedback to a user.

One example of a haptic actuator provides mechanical motion in responseto an electrical stimulus. Some haptic feedback mechanisms usemechanical technologies such as vibratory motors, like a vibrating alertin a cell phone, in which a central mass is moved to create vibrationsat a resonant frequency. Other haptic feedback mechanisms use forcegenerating devices attached to a touchpad or touchscreen to generatemovement that may be sensed by a user. The quality of the hapticfeedback may depend upon the mechanical and electrical interconnectionsbetween the haptic feedback mechanism and the touchscreen.

SUMMARY

Tactile feedback may be provided using an actuator connected to atouchpad. The actuator may be controlled by actuator drive signals. As auser of an electronic device interacts with the touch pad, the user maymake gestures and perform other touch-related tasks. When the userdesires to select an on-screen object or perform other tasks of the typetraditionally associated with button or keypad actuation events, theuser may press downwards against the surface of the track pad. Whensufficient force is detected, appropriate action may be taken and drivesignals may be applied to the actuator.

The actuator may impart movement to the touch pad. For example, theactuator may drive a coupling member into an edge of the planar touchpad member. Flexible pads may be formed under the force sensors to helpallow the touch pad member to move laterally (in-plane with respect tothe plane of the planar touch pad member) when the actuator is inoperation. This may improve actuator efficiency. The actuator may movethe touch pad in response to button press and release events or inresponse to satisfaction of other criteria in the electronic device.

One embodiment of the present disclosure may take the form of a methodfor providing haptic feedback in an electronic device. The methodincludes sensing a first input force by a sensor and providing, via afeedback mechanism, a first feedback corresponding to the first inputforce, sensing a second input force by the sensor that is at leastpartially in an opposite direction from the first input force, andproviding, via the feedback mechanism, a second feedback correspondingto the second input force.

Another embodiment of the present disclosure may take the form of ahaptic device for an electronic device. The haptic device includes asensor configured to sense a user input and a feedback mechanism incommunication with the sensor. The feedback mechanism is configured toprovide feedback to a user. The feedback may be varied by the feedbackbased upon input sensed by the sensor.

Yet another embodiment of the present disclosure may take the form of atrack pad for a computing device, the computing device including aprocessor. The track pad includes a touch assembly defining a user inputsurface and a sensor in communication with the processor. The sensor isconfigured to sense user force on the touch assembly. The track padfurther includes an actuator connected to the touch assembly andconfigured to selectively impart movement to the touch assembly. Theactuator moves the touch assembly in a direction and at a speed toprovide feedback to a user, where the feedback is based, at least inpart, on a magnitude and an acceleration of the down-stroke user inputforce.

The quality of the haptic feedback provided by the actuator is directlyrelated to the quality of the interconnection of the actuator to thetouch assembly. Secure electrical and mechanical connections of theactuator to the touch assembly are essential to provide the kind ofhaptic feedback necessary for a quality user experience. In someembodiments, mechanical fasteners such as screws and washers may be usedto provide secure electrical and mechanical interconnections between theactuator and the touch assembly of the track pad.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electronic device including a trackpad;

FIG. 2 is a block diagram illustrating a computer system;

FIG. 3 is a schematic showing a touch assembly which includes touchpadconnected to an actuator by a force assembly;

FIG. 4 is an exploded view of one embodiment of a force assembly, touchassembly, and actuator;

FIG. 5 is a side view of the embodiment illustrated in FIG. 4 shown inan assembled implementation with an actuator interconnected with a forceassembly;

FIG. 6 is a side view of one embodiment of an interconnect point of FIG.5;

FIG. 7 is a side view of an alternate embodiment of an interconnectpoint of FIG. 5;

FIG. 8, is one embodiment of the electromagnetic connection between theactuator and device board;

FIG. 9 is an exploded view of an alternate embodiment of a forceassembly, touch assembly, and actuator assembly;

FIG. 10 is an assembled view of the embodiment of FIG. 9;

FIG. 11 is a side sectional view of the assembly of FIG. 10 taken alongthe lines 11-11;

FIG. 12 is a flow chart illustrating one method for manufacturing atrack pad; and

FIG. 13 is a flow chart illustrating an alternate method formanufacturing a track pad.

DETAILED DESCRIPTION

The present disclosure may be understood by reference to the followingdetailed description, taken in conjunction with the drawings as brieflydescribed below. It is noted that, for purposes of illustrative clarity,certain elements in the drawings may not be drawn to scale. Likereference numerals denote like structure throughout each of the variousfigures.

When a user interacts with a portable electronic device, he or she maybe asked to provide certain inputs to the portable electronic device inorder for that device to determine the needs and/or wishes of the user.For example, a user may be asked to indicate which of variousapplications (apps) that the user wishes to access. These apps may beicons on a touchscreen and the user may touch one of these icons toselect and access that app. A user may also be prompted to adjustcertain functions of the portable electronic device such as sound,picture quality, and the like. This may be done by touching an indicatordisplayed on a touchscreen and associated with that function. In someapplications on a portable electronic device, a user may be prompted totouch numbers or letters on a touchscreen to provide specific input tothe portable electronic device. For example a user may spell a word orcomplete a form by entering a mark in a certain location.

In all of the above situations, a user wants to ensure that theappropriate app icon or portion of the screen that represents his or hertrue intention is touched. In order to satisfy this need forconfirmation, the user may desire physical confirmation of this touch.Such physical confirmation could be made visually by the portableelectronic device, which may confirm on a display screen that the userinstructions have been received. Similarly and in some embodiments, theuser may wish to receive physical confirmation in the form of hapticfeedback from the portable electronic device that his or her commands orinputs have been received. This feedback may be made in the form oftactile feedback by applying forces, vibrations or motions from theportable electronic device to the person of the user. In someembodiments, this force or vibration is applied to the body part of theuser that is in contact with, or otherwise accessible by, the portableelectronic device. In some embodiments, this accessible portion is thefinger or fingers of a user that may be in contact with the touchscreenof the device during the process of making the selection of the app orother function that he or she wishes to select. In order to provide thishaptic feedback, some portable electronic devices may incorporateactuators that apply forces or motion to a track pad or touchscreen andin turn to provide touch feedback to a user.

Generally, embodiments described herein may take the form of a hapticassembly for providing haptic feedback to a user. A haptic actuator mayprovide the haptic output in response to an input signal or an outputsignal, or as part of an output signal. The actuator may vary its outputin order to shape and control the haptic response and thus the sensationexperienced by a user. In some embodiments, the actuator may beelectromagnetically controlled. Embodiments described herein may beincorporated into a variety of electronic or electrical devices, such asa track pad, mouse, display, or other input (or output) device. Thehaptic device may be incorporated into an electronic device such as alaptop computer, smart phone, digital music player, tablet computingdevice, portable computing device, feedback or outputs for appliances,automobiles, touchscreens, and the like.

Referring to FIG. 1, a portable electronic device may take the form of alaptop computer system 11 and typically includes a display 21 mounted ona housing 22. Display 21 may provide an image or video output for theelectronic device 11. Display 21 may be substantially any size and maybe positioned substantially anywhere on the electronic device 11. Insome embodiments, the display 21 may be a liquid crystal display screen,plasma screen, light emitting diode screen, and so on. The display 21may also function as an input device in addition to displaying outputfrom the electronic device 11. For example, display 21 may includecapacitive touch sensors, infrared touch sensors, or the like that maycapture a user's input to the display 21. In these embodiments, a usermay press on the display 21 in order to provide input to the electronicdevice 11. In alternate embodiments display 21 may be separate from orotherwise external to the electronic device 11, but may be incommunication therewith to provide a visual output for the electronicdevice.

Referring again to FIG. 1, computer system 11 further may include userinterfaces such as a keyboard 23 to allow a user to provide input tocomputer system 11. For example, one type of input may be a user's touchor amount of force exerted on a track pad 14 by a user's finger 24, andanother type of input may be based on an accelerometer within theelectronic device 11. In addition to varying the feedback provided to auser, the haptic device and/or the processor of the electronic devicemay register different inputs to the haptic device differently. In otherwords, as the user varies his or her input to receive different types offeedback, those various inputs may also be registered by the system asdifferent from one another.

FIG. 2 is a schematic illustrating a computer system including a hapticdevice in accordance with a sample embodiment. The computer system 11includes a processing unit 12, a controller 13, and a track pad 14.Controller 13 may execute instructions and carry out operationsassociated with portable electronic devices as are described herein.Using instructions from device memory, controller 13 may regulate thereception and manipulation of input and output data between componentsof electronic device 11. Controller 13 may be implemented in a computerchip or chips. Various architectures can be used for controller 13 suchas microprocessors, application specific integrated circuits (ASICs) andso forth. While computer system includes a processor 12 and controller13, in some embodiments the functions of controller 13, as describedherein, may be implemented by processing unit 12 and controller 13 maybe omitted. Controller 13 together with an operating system may executecomputer code and manipulate data. The operating system may be awell-known system such as iOS, Windows, Unix or a special purposeoperating system or other systems as are known in the art. Controller 13may include memory capability to store the operating system and data.Controller 13 may also include application software to implement variousfunctions associated with portable electronic device 11.

Track pad 14 may include at least one optional position sensor 16, atleast one touch sensor 17, and at least one force sensor 18, and one ormore actuators 19 as well as a track pad plate surface 15. Touch sensor17 may, in some embodiments be a capacitive sensor that senses a fingeror other touch through either mutual or self-capacitance. In otherembodiments, a strain gauge, resistive sensor, optical sensor, and thelike may be used to sense a touch.

In some embodiments, the position sensor(s) 16 may be an accelerometer,motion sensor, optical sensor, Hall sensor, capacitive sensor, or thelike. Each of the touch sensor(s) 17, the position sensor(s) 16, theforce sensor(s) 18 and actuator 19 are coupled to the track pad 14 andcontroller 13 and/or processing unit 12. Force sensors 18 may beconfigured to determine an input force that may be exerted on the hapticdevice by a user, and the acceleration sensor 16 may be configured todetermine an input speed and/or acceleration of the input force exertedon the haptic device by the user.

Touch sensors 17, which, in one embodiment, may be capacitive sensors,may determine the location of one or more touches by a user on thehaptic device. The touch sensor(s) 17 and the force sensor(s) 18 detectthe location and force of the touch on the track pad 14 respectively andsend corresponding signals to the controller 13. The actuation member 19may be in communication with processor 12 and/or the input sensors andmay provide movement to all or a portion of the surface of track pad 14in response to one or more signals from the processor. For example, theactuator 19 may be responsive to one or more input signals and move thefeedback surface in various manners based on the one or more inputsignals. It should be appreciated that the force sensor(s) 18 may detectnon-binary amounts of force. That is, exerted force may be detectedacross a continuum of values ranging from a minimum to a maximum. Theforce may be absolutely determined or correlated within this continuum,or the force may be assigned to one of a number of levels or bandswithin the continuum. In this manner the track pad 14 may be differentfrom a switch or other conventional input device that is either closedor open, or on or off, or the like.

In some embodiments, the force sensor 18 may be a capacitive sensor.Such a sensor may detect force either through mutual capacitance orself-capacitance. The force sensor 18 may include multiple electrodesseparated by a gap, in one embodiment. The electrodes may be formed inan array, as sheets, a single pair of electrodes, a structure dividedinto subsets of electrodes, and so on. Typically, the gap separatespaired electrodes (e.g., one electrode of each pair is located at acorresponding side of the gap) although this is not necessary. The gapmay be an air gap, a gel, a foam, and so on.

As a force is exerted on a surface of the haptic device (or otherassociated device), the gap may compress and the electrodes on eitherside of the gap may move closer to one another. The reduction indistance between the electrodes may increase a capacitance between theelectrodes; this increase in capacitance may be correlated to the forceexerted on the surface. Alternately, a single row or layer of electrodesmay be positioned on one side of the gap. Capacitance between an objectexerting force on the surface and one or more electrodes may increase asthe gap decreases, which occurs as the force increases. Again, thechange in capacitance may be correlated to an exerted force. It shouldbe appreciated that increases in distance (e.g., increases in gap) maybe correlated to decreasing force.

In still other embodiments, the force sensor 18 may be an ultrasonicforce sensor. Ultrasonic energy may be emitted toward the surface of thetrack pad 14 (or other structure or device). The amount of reflectedenergy may vary as an object contacts the surface and/or as an objectexerts force on the surface. Accordingly, the amount of energy receivedby an ultrasonic receiver maybe correlated to an exerted force.

In yet other embodiments, the force sensor may be an optical forcesensor, a resistive force sensor, a strain sensor, a pyroelectricsensor, and so on. As another example, the force sensor 18 may be one ormore strain gauges. As force is exerted on the structure, the force maybe transmitted through one or more legs or other supports. These legsmay bend or otherwise deflect in response to the exerted force. A straingauge may be mounted to a leg, or one strain gauge to each leg, or anycombination of strain gauges may be mounted to any combination of legs.Deformation of the legs may bend the strain gauges and thus induce ameasurable strain. The greater the exerted force, the greater thedeformation and the greater the strain. In this manner, strain may becorrelated to force in a non-binary fashion.

As one example of the foregoing, FIG. 4 shows an exploded view of asample track pad with the outer surface of the pad at the bottom of thefigure (e.g., the exploded view is upside down such that the interior ofthe track pad is at the top of FIG. 4). The force assembly 26 may definemultiple legs therein and a strain gauge may be mounted on each leg. Asforce is exerted on the track pad surface, the legs formed in the forceassembly 26 may deflect or deform in the aforementioned manner. Each legmay have a strain gauge mounted thereon (not shown) to measure thecorresponding strain in order to estimate an exerted force.

Some embodiments described herein may take the form of a haptic devicefor use with an associated electronic device such as computer system 11.The haptic device may vary output provided to the user based on a numberof different inputs to the haptic device. Additionally, the hapticdevice may vary one or more inputs provided to the computer device 11based on the user inputs. Inputs to computer device 11 may include aprocessor or device command based on a system state, applicationactivity, sensor data, and so on. Thus, the haptic device may adapt thefeedback, as well as the types of input provided to computer 11 from thehaptic device, based on one or more characteristics, settings, or inputs(as provided to a particular application).

As another example, the haptic device may provide varying feedbackdepending on the particular application running on the electronicdevice, the force input member (e.g., index finger, thumb, palm of theuser), the amount of input force, the speed or acceleration of the inputforce, the length of time an input force is applied, location of theelectronic device, and/or various other types of data inputs that may beprovided to the haptic device, to the electronic device, or acombination of both. It should be noted that the data inputs to vary theoutput of the haptic device may be provided by a user, the hapticdevice, and/or the electronic device 11.

One embodiment for providing haptic feedback is described below. Whenusing track pad 14 to provide input to the computer system 11, a usermay move his or her finger 24 on track pad 14 to a desired location. Theuser may also touch track pad 14 at a desired location to provide input.Touch sensor(s) 17 and the force sensor(s) 18 detect the location andforce of the touch on track pad 14 respectively and generatecorresponding signals sent to the controller 13. Controller 13communicates with processing unit 12 inside computer system 11 andprocessing unit 12 may generally instruct controller 13 with respect tocertain operations. As one non-limiting example, processing unit 12 andcontroller 13 in combination may use these signals to determine if thelocation of the touch correlates with a specific application or a userinterface (UI) element. If the location is within the range for thespecific application or Ul element, processing unit 12 furtherdetermines if the force signal is above a threshold. If so, processor 12may validate the force signal as a selection of the application of UIelement. In other words, if the force signal is not a false signal, thencontroller 13 activates actuator 19, which moves the surface of thetrack pad 14 beneath the user's finger 24. The user may sense thismotion, thereby experiencing haptic feedback in response to theapplication or Ul element selection. Position sensor 16 detects how muchtrack pad 14 moves relative to the actuator 19 after an actuation event,or vice versa, and may be omitted in some embodiments.

In another embodiment, track pad 14 may detect a user input, such as auser touch or a user force. In this example, substantially any type ofdetected user input may be used to provide feedback to the user. Basedon the user input, track pad 14 may be activated by the processor 12 tomove or vibrate to provide haptic feedback to a user. In some instances,the user input may be correlated to a specific application or UIelement, in which case the location of the user input may be analyzed todetermine if feedback is desired. In other instances, the mere detectionof a user input may be sufficient to initiate haptic feedback. It shouldbe noted that haptic feedback may be provided in response not only to auser input, an example of which is provided above, but also in responseto system operation, software status, a lack of user input, passage ofuser input over Ul elements(s) (e.g., dragging a cursor over a window,icon, or the like), and/or any other operating condition of computersystem 11.

Referring to FIG. 3, a schematic of a track pad 14 with an actuator 19is shown. As mentioned above, the quality of the haptic feedbackprovided to a user may depend upon the quality of the interconnections,both electrical and mechanical, that secure actuator 19 to theuser-sensing surface, which may be track pad 14. In one embodiment, oneor more actuators 19 are positioned below track pad 14 and coupledthereto by a force assembly 26 to provide vibratory or other motion totrack pad 14. In another embodiment, actuators 19 may be positionedapart from track pad 14 and coupled by a force assembly 26 thereto. Thecoupling of track pad 14 to actuator 19 by force assembly 26 in eitherembodiment will be described in more detail below with respect to FIGS.4-13.

Referring to FIG. 4, in one embodiment, an exploded view of an inputdevice including a force assembly, 26, touch assembly 25, and actuator19, is shown. An attraction plate 27 and an electronic device board 28are also shown. The interaction of actuator 19 and attraction plate 27provide a haptic output to touch assembly 25 when the actuator 19 isenergized; generally, the actuator may magnetically attract theattraction plate 27, thereby moving the track pad 14. When the actuator19 is de-energized, it no longer magnetically attracts the plate 27 andthe track pad 14 may be returned to its neutral/unloaded position by arestoring force exerted by a gel plate or gel structures.

The attraction plate 27 may be affixed to the force assembly while theactuator is affixed to the touch assembly 25 or other surface of thetrack pad. Flexible structures 52 may attach the track pad (and morespecifically a structural layer of the track pad) to the arms formed inthe force assembly 26. The flexible pads may transmit a force exerted onthe surface of the input device to the legs, shown as extensions withinC-shaped cuts formed in the force assembly 18. Force sensors 18 mountedon the legs may measure the force. Typically, the force sensors 18 maybe positioned near the contact point of the flexible structures 52 withthe legs, although this is not necessary.

The legs may be formed unitarily with the rest of the force assembly 26by cutting a series of C-shaped trenches into the force assembly; eachsuch trench defines a unique leg in the current embodiment. The forceassembly 18 may be connected to a structural part of an associatedelectronic device, such as an interior plate or housing. Thus, the legsmay permit some flexure or displacement of the track pad surface withrespect to the force assembly by bending or otherwise deforming. Aspreviously mentioned, this deformation may be sensed by one or moreforce sensor 18 and used to determine or estimate an exerted force.

A support structure may sit between the flexible structures 52 and thetouch assembly 25. The support structure may be formed as a square orrectangle with diagonal cross beams forming an X-shape in the middle ofthe support structure (e.g., extending from one diagonally opposingcorner to another). This particular shape may stiffen the track padwhile still permitting the transfer of force to the force sensor(s) 18and may be lighter than a planar support structure.

Referring to FIG. 5, a side view of the embodiment illustrated in FIG. 4is shown in an assembled implementation with actuator 19 interconnectedwith force assembly 26 at interconnect points 29 which will be furtherdescribed below in FIGS. 6 and 7. Actuator 19 is also securelyconnected, both electromagnetically and mechanically to board 28 atinterconnect points 31 which will be further described below in FIG. 8.As stated above, the secure interconnection of actuator 19 to both forceassembly 26 and electronic board 28 is important to ensure that qualityhaptic feedback is provided to a user of electronic device 11 byinteracting with touch pad assembly 25 including track pad 14 surface.

Referring to FIG. 6, in one embodiment, a side view of interconnectpoint 29 of FIG. 5 is shown in an expanded view. Actuator 19 is shownmechanically interconnected to force assembly 26 by a mechanicalfastener such as a screw 32. Screw 32 may be threaded into insert 33which is attached to, and part of, force assembly 26. Insert 33 may beglued, press fit, or otherwise attached to force assembly 26. A spacer34 may be included between actuator 19 and force assembly 26 tofacilitate connection of actuator 19 with force assembly 26. This securemechanical interconnection between actuator 19 and force assembly 26results in vibrational, lateral, or other movement by actuator 19 beingefficiently transferred to force assembly 26 and thence to touchassembly 25 such that a user may benefit from haptic feedback asdescribed herein.

Referring to FIG. 7, a side view of an alternate embodiment ofinterconnect point 29 of FIG. 6 is shown in an expanded view. In thisembodiment, in addition to screw 32 which is threaded into insert 33 andused to connect actuator 19 to force assembly 26, a washer 35 may beused to further interconnect actuator 19 to force assembly 26. Washer 35may be a plastic ring that is press fit into a recess 36 in actuator 19.Threaded insert 33 fits into washer 35 such that shifting movement ofactuator 19 with respect to force assembly 26 is minimized oreliminated. That is, tighter tolerances than would otherwise beachievable may be maintained by use of washer 35 which in oneembodiment, may be a plastic ring which may be pliable so as to reduceor eliminate gaps between insert 33 and actuator 19. Movement ofactuator 19 in the lateral direction as indicated by arrows 37 may thusbe accomplished without movement of actuator 19 in recess 36 betweenactuator 19 and insert 33.

Referring to FIG. 8, in one embodiment, the electromagnetic connectionbetween actuator 19 and device board 28 is illustrated by an expandedview of interconnect points 31 from FIG. 5. In one embodiment, anelectrically conductive mechanical fastener such as a screw 38 is usedto connect actuator 19 and circuit board 28 through an electricallyconductive emboss element 39. Screw 38 provides an electrical path fromactuator printed circuit board (PCB) 41 to embossed portion 39 then toscrew 38 and thence to circuit board 28. In this manner a secureelectromagnetic interconnection may be made between circuit board 28 andactuator board 41.

Referring to FIG. 9, an exploded view of an alternate embodiment of aninput device including a force assembly 42, touch assembly 43, andactuator 44, is shown. An attraction plate 45 and an electronic deviceboard 46 are also shown. The interaction of force assembly 42, actuator44, and attraction plate 45 provide the force to touch assembly 43 asenergized through device board 46 and generally as described above withrespect to other embodiments. Touch assembly 43 includes glass coverlayer/top plate 47, touch sensor layer 48 and touch grounding layer 49,which may also be a stiffening or structural support layer in certainembodiments. An electrostatic discharge clip (or other structure) 51 maybe attached between attraction plate 45 and force sensor assembly 42. Insome embodiments, the clip 51 may be made from metal, a conductivealloy, a conductive ceramic, a stiff nonconductive material having aconductive path formed therein, or the like. In other embodiments, theclip 51 may be formed from a conductive fabric and attached to the plate45 and assembly 42 with a conductive adhesive. The use of a conductivefabric may permit the clip 51 to move, bend or flex with operation ofthe device or as components shift with respect to one another over time.

The force assembly 42 may be H-shaped, as shown in FIG. 9. This shapemay permit or enhance localized bending of the force assembly in aregion or regions occupied by the force sensor(s) 18, thereby enhancingthe ability of the sensor(s) to detect force. Insofar as the forcesensor(s) are located on the underside of the force assembly in the viewshown in FIG. 9, they are not visible in the figure.

Certain embodiments may incorporate a stiffener to stiffen and/orstabilize any or all of the force assembly 42, touch assembly 43,actuator 44, and/or top plate 47. The stiffener 50 may be affixed to anyof a number of elements of the force assembly 42. For example, it may beattached to the force assembly 42 near or adjacent to the attractionplate 45. In other embodiments, the stiffener may be affixed between theforce sensor assembly 42 and the top plate 47 (or a touch assembly,flex, adhesive or other layer affixed to the top plate 47). Such anembodiment is shown in cross-section in FIG. 11, for example. Thestiffener 50 may be formed from any suitable material, examples of whichinclude carbon fiber, steel, aluminum, ceramics, and so on. Thestiffener 50 may be used in a variety of embodiments, including thatshown in FIG. 4.

Referring to FIG. 10, the exploded view of FIG. 9 is shown assembled andfrom a bottom view. Circuit board 46 is soldered to actuator 44 atsolder pads 53 to provide the electrical power connection for actuator44. Force assembly 42 contacts touch assembly 43 at flexible pads 52(FIG. 9) which may be compliant foam or gel pads. Thus, force assembly42 may move laterally at least somewhat with respect to top plate 47,insofar as lateral motion of the force assembly 42 may apply a shearforce to the gel or foam pads 52.

Actuator 44 is securely mechanically attached to board 46 by a pair ofscrews 54. This secure mechanical interconnection between actuator 44and board 46 results in vibrational, lateral, or other movement byactuator 44 being efficiently transferred to force assembly 42 and thento touch assembly 43 through actuator 44 and attraction plate 45 whichis securely fastened to force assembly 42 by a pair of pins 55 shown inFIG. 10. This secure interconnection ensures that a user may benefitfrom more precise haptic feedback as described herein.

Referring to FIG. 11, a side sectional view of the assembly taken alongthe lines 11-11 in FIG. 10 is shown. Screw 54 is shown mechanicallysecuring actuator 44 to device board assembly 46. To provide hapticfeedback, actuator 44 electromagnetically moves attraction plate 45 thatis secured to force assembly 42 at pins 55. Moving force assembly 42 inturn causes haptic feedback by moving the overall structure of the trackpad. It should be appreciated that the force assembly 42 is connected tothe touch assembly 43 by gel pads 52 while actuator 44 is affixed toboard 46 and, ultimately, to plate 49 by mechanical fasteners. Thus,when actuator 44 magnetically attracts actuation plate 45, the two maymove closer to one another. This may induce a motion in the touchassembly 43, since it is rigidly affixed to the actuator 44.Essentially, the actuator 44 may move towards the attraction plate 45,which may be rigidly and/or fixedly connected to a portion of anenclosure or otherwise prevented from moving.

The motion of the actuator 44, board 46 and touch assembly 43 toward theplate 45 and force assembly 42 causes the gel pads 52 to shear. When theactuator is de-energized, the gel pads exert a restoring force thatmoves the actuator (and thus the majority of the track pad, includingtouch assembly) away from the attraction plate 45. Accordingly, rapidlyenergizing and de-energizing the actuator may cause the track pad torepeatedly move back and forth quickly, thereby providing a hapticoutput to a person touching the track pad.

By securely attaching actuator 44 to board assembly 46, the electricalinterconnections, which may be solder joints 53, do not loosen or severfrom either device board assembly 46 or actuator 44. Thus, hapticfeedback can be securely and reliably provided to finger 24 of a user oftrack pad 14 on an electronic device such as device 11.

Referring to FIG. 12, a method for manufacturing a track pad including ahaptic feedback device includes providing a touch assembly at step 56which may include a ground plate 49 that may also provide structuralstiffness to the track pad, a sensor plate, and a glass plate forcontact by a user's person. At step 57, an actuator is connected to theforce assembly. In some embodiments the actuator may be mechanicallyconnected by screws to provide secure interconnection of the actuatorwith the force assembly. This secure mechanical interconnection betweenactuator and force assembly results in vibrational, lateral, or othermovement by the actuator being efficiently transferred to the forceassembly. In some embodiments a washer may be used to furtherinterconnect the actuator to the force assembly. The washer may be aplastic ring that is press fit into a recess in the actuator. A threadedinsert may be used to fit into the washer such that shifting movement ofthe actuator with respect to the force assembly is minimized oreliminated. That is, tighter tolerances than would otherwise beachievable may be maintained by use of the washer, which in oneembodiment may be a pliable plastic ring may be that reduces oreliminates gaps between the insert and the actuator.

At step 58, a device board is securely connected to the force assemblyalso by means of screws. In one embodiment, an electrically conductivescrew is used to connect actuator and circuit board through anelectrically conductive emboss element. Screw provides an electricalpath from the actuator printed circuit board (PCB) to the embossedportion and then to the screw and circuit board. In this manner a secureelectromagnetic interconnection may be made between the circuit boardand the actuator board. The touch assembly is associated with a forceassembly in step 59 which may include placement of flexible pads 52,which may be a foam or gel pad, between the force assembly and the touchassembly.

Referring to FIG. 13 an alternate method for manufacturing a track padincluding a haptic feedback device includes providing a touch assemblyat step 61 which includes glass cover layer, plastic (PET) touch sensorlayer, and a touch grounding layer which may also provide structuralstiffness in certain embodiments. At step 62, a circuit board issoldered to the actuator to provide the electrical power connection foractuator. In some embodiments the actuator may be securely mechanicallyconnected to the circuit board by screws.

In step 63, the attraction plate is securely fastened to the forceassembly by pins, thereby resulting in vibrational, lateral, or othermovement by the actuator being efficiently transferred to the forceassembly and then to the touch assembly through the actuator. In step64, the touch assembly is associated with the force assembly that mayinclude the placement of flexible pads 52 which may be one or more foamor gel pads between force assembly and touch assembly.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not intended to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

We claim:
 1. An electronic device configured to provide haptic feedbackand comprising: a housing defining an aperture; and a trackpad at leastpartially within the aperture and comprising: an input surface movablein a plane parallel to an external surface of the housing; a forcesensor assembly below the input surface; an attractor attached to theforce sensor assembly; an electromagnetic actuator mechanicallyinterconnected to the input surface and configured toelectromagnetically interact with the attractor; and an electricalcircuit in communication with the electromagnetic actuator; wherein: inresponse to a signal, the electrical circuit is configured to apply acurrent to the electromagnetic actuator to attract the attractor andcause the input surface to translate in the plane.
 2. The electronicdevice of claim 1, wherein the input surface is operative to provide ahaptic output by translating in the plane.
 3. The electronic device ofclaim 1, wherein the signal is associated with an input provided by auser when the user is exerting a force on the input surface.
 4. Theelectronic device of claim 1, wherein the current applied to theelectromagnetic actuator varies based on the signal.
 5. The electronicdevice of claim 1, wherein the electromagnetic actuator comprises one ormore electromagnets configured to attract the attractor.
 6. Theelectronic device of claim 5, wherein the electromagnetic actuatorcomprises one or more core elements within the electromagnets.
 7. Theelectronic device of claim 1, wherein the force sensor assemblycomprises four force-sensitive elements positioned along a periphery ofthe input surface.
 8. The electronic device of claim 1, wherein theinput surface is coupled to the force sensor assembly by a compliantstructure.
 9. A touch input device configured to provide haptic feedbackcomprising: a force assembly comprising a group of force sensors; aninput surface coupled to and at least partially supported by at leastone flexible pad coupled to the force assembly; an attraction platemechanically attached to the force assembly; an electromagnetic actuatormechanically attached to the force assembly and configured toelectromagnetically interact with the attraction plate, causing theinput surface to translate in a plane; an electronic board electricallyand mechanically attached to the electromagnetic actuator; and aflexible circuit coupling each of the group of force sensors to theelectronic board; wherein in response to an actuator drive signal, theelectronic board is configured to apply an electrical signal to theelectromagnetic actuator to cause the attraction plate to move towardthe electromagnetic actuator.
 10. The touch input device of claim 9,wherein a magnitude of movement of the attraction plate varies based onthe actuator drive signal.
 11. The touch input device of claim 9,wherein the actuator drive signal corresponds to a haptic feedbacksignal.
 12. The touch input device of claim 9, wherein the input surfacecomprises glass.
 13. The touch input device of claim 9, wherein theinput surface is included in a touch assembly, the touch assemblyfurther comprising a touch sensor layer disposed below the inputsurface.
 14. The touch input device of claim 9, wherein the forceassembly comprises an H-shaped structure.
 15. The touch input device ofclaim 14, wherein the group of force sensors comprises fourforce-sensitive elements associated with and coupled to differentlocations along the H-shaped structure.
 16. The touch input device ofclaim 9, wherein: the electromagnetic actuator is mechanically attachedto the force sensor assembly through a mechanical fastener; and theelectronic board is electrically and mechanically attached to theelectromagnetic actuator by the mechanical fastener, wherein in responseto the actuator drive signal, the electronic board is configured toapply the electrical signal to the electromagnetic actuator through themechanical fastener to cause the attraction plate to move toward theactuator.
 17. A method of providing haptic feedback to a user of a touchinput device, the method comprising: detecting, with a force assembly, aforce exerted on an input surface of the touch input device; providing acurrent from a circuit board to an electromagnetic structure of anactuator through a mechanical fastener connecting the actuator to thecircuit board, the actuator positioned adjacent to an attractor plate ofthe input surface; and magnetically attracting the attractor platetoward the electromagnetic structure, thereby causing the input surfaceto translate in plane.
 18. The method of claim 17, wherein the operationof magnetically attracting the attractor plate toward theelectromagnetic structure comprises providing an alternating current tothe electromagnetic structure, thereby causing the input surface tovibrate in a plane.
 19. The method of claim 17, further comprisingdetecting, with a touch sensor, a user touch on the input surface. 20.The method of claim 17, wherein the current is provided by an electroniccircuit coupled to the force assembly.